Apparatus for feeding damping fluid into guide tubes in multiple-spindle turning machines and the like

ABSTRACT

The feeding apparatus has a holding plate (15) which is provided with passage bores (18) for the accommodation and mounting of the rear end of the guide tubes (12) of the turning machine. The holding plate (15) is mounted on a supporting frame (16) for rotation about the central axis of the spindle drum of the turning machine. On the side of the holding plate (15) facing away from the spindle drum there is a cover plate (26) which is coupled non-rotatably to the supporting frame (16) and which is sealed against the holding plate (15). Between the holding plate (15) and the cover plate (26) is a distribution passage (38) with which on the one hand the openings of the guide tubes (12) are in communication and to which on the other hand a damping fluid feed line is connected. Advantageously, a passage bore (42) is present in the cover plate (26) in the alignment of one of the guide tubes (12), and can be closed by a closure (43) whose passage width is at least approximately equal to the largest diameter of the workpieces.

Multiple-spindle turning machines have a number of rod guides for therod-like workpieces which are fed to the working spindles section-wisefrom the rear end of the turning machine. This feed is usually performedmechanically by means of collets. The rod guides are generally in theform of tubes into which the rods are loaded from the rear end into thecollets, which are situated within the working spindles and rotate withthem. The tubes do not rotate. The rod-like workpieces, however, rotatewith the working spindles. Consequently, the section of the length ofthe workpieces situated in the guide tubes rotate with respect to thetubes. To prevent the wear on the workpieces and on the tubes themselvesfrom being too great in this relative movement, and also to keep thenoise as low as possible, a damping fluid with lubricating properties ismade to flow through the guide tubes. This damping fluid must be fedindividually to the rear end of the guide tubes.

In a known feeding apparatus (DE-U 88 14 860.2) the rear end of theguide tubes is fastened to a common holding plate. This holding platehas an axial bore to receive and hold each guide tube. The holding plateis journaled for rotation about the central axis of the spindle drumwith which it rotates circumferentially to a certain degree each timethe workpieces change station. The bearing of the holding plate is in asupporting frame.

The bearing of the holding plate is formed by a cylindricalcircumferential surface on the supporting frame and one on the holdingplate which are fitted to one another. In the area of these commonbearing surfaces a circumferential distributing groove is present, whichis connected to a line feeding the damping fluid. Seals are present onboth sides of the distributing groove which seal the annular intersticebetween the two circumferential surfaces from the exterior. Within theholding plate connecting passages are present which connect thedistributing groove to the interior of each of the guide tubes. Each ofthe guide tubes is closed at its end with a cap closure which isremovably attached to the holding plate where it surrounds the guidetube.

Aside from the fact that, in this apparatus, the bearing and sealingsurfaces provided for the holding plate have a comparatively largediameter and therefore the seals used in them are very expensive, thisapparatus also has the disadvantage that the guide tube cap closures onthe holding plate have to be removed individually in a change ofworkpieces to enable another workpiece to be introduced.

Another great disadvantage of this apparatus is that the cap closuresprotrude outwardly in the axial direction beyond the end face of theholding plate. Since the holding plate rotates sectionally with thespindle drum, the cap closures also rotate whenever the spindle drumturns. This represents a not inconsiderable hazard for the operatingpersonnel if they accidentally stand near the holding plate, plus thefact that it is precisely in the area of the rear end of the guide tubesthat there is little room available and the operating personnel haslittle freedom of movement.

The invention specified in claim is addressed to the problem of creatingan apparatus for feeding the damping fluid into guide tubes inmultiple-spindle turning machines and the like, in which the danger ofaccidents due to exposed rotating parts will be reduced or eveneliminated and the loading of the guide tubes will be facilitated, andthat furthermore the structural requisites for an automated loading ofthe tubes will be created.

In the feeding apparatus according to claim 1, the cover platecompletely covers the back end of the holding plate. Since the coverplate is still, even when the spindle drum and the holding plate arerotating, there are no exposed parts which perform a rotatory movement.Thus any danger of injury to the operating personnel by rotating partsis eliminated.

To reload workpieces, either the cover plate is removed as a whole, or alid-like part of it is removed, while the part with the gasket againstthe holding plate remains in place. When the cover plate is removed orwhen the lid is removed, the guide tubes are freely accessible forreloading.

In an embodiment of the feeding apparatus according to claim 2, it is nolonger necessary for the entire cover plate or lid to be removed, butonly the parts of the cover whose dimensions are only slightly largerthan the passage bores in the guide tubes.

Even if the cover parts or the fasteners serving to attach them to thecover plate should protrude past the back end of the cover plate, thereis still no danger of injury, since these cover parts are also still,together with the cover plate.

In an embodiment of the feeding apparatus according to claim 3, theopening and closing of the cover parts can be performed mechanically.The opening and closing movements can even be automated. This createsthe possibility of using an automatic loader for the rod-likeworkpieces.

In an embodiment of the feeding apparatus according to claim 4, nospecial space is needed for operating the cock plug as the closure,because the cock plug is merely rotated on its axis. In a furtherdevelopment of this feeding apparatus according to claim 5, individualsealing rings can be used in order to seal the spherical cock plugagainst the cock housing. These sealing rings can be replaced in case ofnecessity.

With an embodiment of the feeding apparatus according to claim 6,loading with fresh workpieces can again be automated, and an automaticloading apparatus can be used for the purpose.

In an embodiment of the feeding apparatus according to claim 7, it isbrought about that the guide tube situated in the loading station [at]the rotational position of the spindle drum is shut off from thedistribution passage. When this one guide tube is being loaded,therefore, the distribution passage and the other guide tubes connectedto it can remain full of the damping fluid. The normal pumping pressurecan even be sustained in the damping fluid without allowing the dampingfluid to escape when the guide tube is open for loading. In a furtherdevelopment of this feeding apparatus according to claim 8, the guidetube that is in the loading station can also be immediately refilledwith damping fluid, even though it is separated by the shut-off devicefrom the normal distribution passage.

In a feeding apparatus configured according to claim 9, the guide tubethat is in the loading station can be loaded without the need first toempty this guide tube. First the new workpiece is introduced into thesealing device before the closure, especially the cock, is opened. Afterthe cock is opened the workpiece can be inserted through the plug of thecock, while the sealing device prevents the outward escape of thedamping fluid. As soon as the end of the workpiece has passed the cock,the cock is reclosed. If such a sealing device is also placed on theother side of the cock, the cock can be closed when the end of theworkpiece is still in the area of the second sealing device. In thismanner the amount of damping fluids that escape--which is slightanyway--is still further reduced. In a further development of thefeeding apparatus according to claim 10, the sealing effect of the oneor both of the sealing devices is still further improved.

The invention will be further explained below with reference to a numberof embodiments represented in the drawing, wherein:

FIG. 1 is a perspective view of a multiple-spindle turning machine forrod machining, with a number of guide tubes for the workpieces, and withan apparatus for feeding the damping fluid to the back end of the guidetubes,

FIG. 2 is a rear view of the feeding apparatus according to FIG. 1,

FIG. 3 is a fragmentary horizontal cross section of the feedingapparatus of FIGS. 1 and 2,

FIG. 4 is a cutaway top view of a modified embodiment of the feedingapparatus,

FIG. 5 is a fragmentary horizontal cross section of FIG. 4 with one ofthe parts is another working position,

FIG. 6 is a fragmentary horizontal cross section of a portion of anotherembodiment of the feeding apparatus.

In the multiple-spindle turning machine 10 seen in FIG. 1, a number ofguide tubes 12 extend rearwardly from the spindle drum and the rod-likeworkpieces which are machined by the turning machine are contained inthem. The guide tubes 12 are held at their front end facing the spindledrum 11 by a holding plate 13 which is journaled in a front supportingframe 14. At its back end the guide tubes 12 are held by a rear holdingplate 15 which is journaled in a rear supporting frame 16. Thesupporting frame 16 rests on a base 17 in which, among other things, apump is housed for feeding a damping fluid for the workpieces into theguide tubes 12.

The holding plate 15 has one passage bore 18 for each guide tube 12, andinto it there is inserted an end piece 19 threaded into the guide tube12. This end piece 19, and with it the guide tube 12, is sealed againstthe holding plate 15 by means of a sealing ring 21 which is placed in acircumferential groove in the end piece 19.

On the side of the holding plate 15 facing the turning machine there isa driving disk 22 which is welded at its center to a driving tube 23.The driving tube 23 reaches all the way to the front holding plate, towhich it is affixed. This provides so that, in a step-wise rotatorymovement of the spindle drum and the front holding plate, the rearholding plate 15 will be moved in the same degree without twisting thecomparatively long guide tubes 12. The driving disk 22 is screwed to theholding plate 15.

The back face of the holding plate 15 is protected and closed off by acover plate 25. The cover plate 25 is of bipartite construction tofacilitate its manufacture and its installation. The outer part 26 andthe inner part 27 of the plate are screwed together.

The cover plate 25 has on its outer part 26 an annular collar 28 whoseinside circumferential surface 29 is fitted to the outer circumferentialsurface 31 of the holding plate 15. In the area of the cylindricalcollar 28 there is a circumferential groove into which a sealing ring 32is placed which provides for a sufficient seal between the holding plate15 and the cover plate 25.

The holding plate 15 turns step-wise with the spindle drum of theturning machine. The cover plate 25 is coupled to supporting frame atleast so as to prevent its rotation, so that it remains still.

In order to relieve the stress in the radial direction on the sealingring 32 acting between these two plates, and since it does not have toprovide any guiding function, but needs only to seal, a rolling bearing33 is provided between the holding plate 15 and the inner part 27. Withabutments and retaining rings it is capable of absorbing not only theradial guidance forces but also axial guidance forces, so that the sameaxial relationship is preserved between the cover plate 25 and theholding plate 15.

As it can be seen in FIG. 3, the cover plate 25 has a circular insideface section 34, which is axially spaced away by a certain amount fromthe end face section 35 of the holding plate 15 that is opposite it inthe same radial area. At the inside margin of the inside face section 34the holding plate 15 has a circular collar 36 which is fitted to a stepin the cover plate 25. In this step in the cover plate 25 a sealing ring37 is laid in a circumferential groove of the cover plate 25. In thismanner an annular space is created which is defined in the axialdirection by the inside face section 34 of the cover plate 25 and by theend face section 35 of the holding plate 15, and is defined in theradial direction by the collar 28 of the cover plate 25 and by thecollar 36 of the holding plate 15. This annular space forms adistribution passage 38 for all of the guide tubes 12 whose interioropens into this distribution passage 38.

In the radial area cf the distribution passage 38 a passage bore 39 ispresent in the cover plate 25 (FIG. 2) to which a supply line 41 isconnected on the outside of the cover plate 25 for the damping fluidwhich is delivered by a pump housed in the base 17.

To load the guide tubes 12, a bore 42 is provided in the cover plate 25(FIG. 3) which is aligned on the circle of the axes of the guide tubes12 and therefore is in line with one of the guide tubes 12. This bore 42serves as the loading opening. Therefore it has an inside diameter thatis at least equal to the greatest inside diameter of the guide tubes 12and their end pieces 19 Since the feeding device of the turning machine(seen from the rear) is usually in the 3-o'clock position of the workingstations, the loading opening 41 is also situated in thiscircumferential position on the cover plate 25.

Since the bore 42 serving as the loading opening also opens into thedistribution passage 38, a closure 43 is present, by which the bore 42can be closed from the outside. This closure 43 is formed by thespherical cock plug 44 of a ball cock 45. In FIG. 3 the cock plug 44 isrepresented in its open position to which it is set when the guide tube12 behind it is being loaded.

The cock case 46 has a cylindrical guiding projection 47 which isinserted into the bore 42 of enlarged outside diameter in the coverplate 25. A sealing ring not shown provides for a sufficient sealbetween the cock case 46 and the cover plate 25.

On the outside of the cock case 46 there is fastened an insertion funnel48 which facilitates the introduction of the rod-like workpieces intothe bore of the cock plug 44.

The ball cock 45 has, in a conventional manner, an actuating means 49with a power drive 51 which here is an air drive.

As it can be seen in FIG. 1, a catch pan 52 is disposed under the coverplate, especially below the ball cock 45, in which the damping fluid iscaught if it escapes from the opened ball cock 45 when a guide tube isloaded.

In FIG. 4 and FIG. 5 can be seen an embodiment of the feed apparatuswhich is modified in the area of the loading opening 42, in which it isno longer necessary to empty all of the guide tubes 12 during aworkpiece change, but only the guide tube that is in the loadingstation, and then only when it is to be loaded. The reference numbers ofany parts that differ from the embodiment described previously areprovided with a prime mark.

On the ball cock 45' the guiding projection 47' is very greatlyshortened. Into the bore 42 of the cover plate 25, which is thus madeavailable in its full inside width, a shut-off device 53 is inserted.This device has an annular shut-off means 54. This shut-off means has anaxial passage bore 55 whose inside width is at least equal to the insidewidth of the other bores. In the outer circumference of the shut-offmeans 54, which is fitted to the interior circumference of the bore 42,a circumferential groove is present into which a sealing ring 56 isinserted. At the end facing the holding plate 15 the shut-off means 54has a circular flange 57 in whose annular face 58 is a circumferentialgroove into which a sealing ring 59 is inserted. The end face 58 is incontact with the end face section 35 of the holding plate 15, whichdefines the distribution passage 38 on the side facing the turningmachine. The end face 58 of the shut-off means 54 has a larger diameterthan the bore 18 in the holding plate 15 into which the guide tube 12 isinserted. The sealing ring 59 in the end face 58 also has a largerdiameter. Thus, the passage bore 18 of the holding plate 15, situated inline with the shut-off device 53, is shut off from the distributionpassage 38.

To enable the shut-off device 53 to be always active, a helicalcompression spring 61 is inserted between the shut-off device 54 and theguiding projection 47' of the ball cock 45 and urges the shut-off device54 against the end face section 35.

Since in the turning machine a machining of the workpieces also takesplace in the feed station in addition to an advancing movement, dampingfluid must be fed also to this guide tube 12. Since this is not possiblefrom the distribution passage 38, the spherical plug 44' of the ballcock 45 is provided in one of its spherical sealing surfaces with anadditional bore 62 which leads into the main passage 63 through the cockplug 44'.

On the cock case 46' a bore 64 is present on the one side, whose axis isin line with the center of the ball of the cock plug 44' and is at rightangles to the alignment of the loading opening 42. To this bore 64 aconnecting line is connected on the outside of the cock case 46', andthen is connected to the main feed line 41. In this manner the dampingfluid can pass from the feed line 41 through the passage bore 64 in thecock case 46' into the interior of the cock plug 44' and from therethrough the bore 62 into the guide tube 12, although this guide tube 12is shut off from the distribution passage 38 in the holding plate 15.

By means of the shut-off device 53 explained above, the guide tube 12that is in the position in question is shut off from the distributiontube 38. During the loading procedure this guide tube 12, however, iscompletely open to the exterior when the ball cock 45 is open. In ordereven in this case to prevent escape of the damping fluid, the sealingdevices 65 and 66 can be used. These are inserted ahead of and behindthe ball cock 45. The shut-off device 53 can in this case be dispensedwith.

In the case of the sealing device 65, a cylindrical recess 68 is presentinside of a sleeve-like casing 67. Into it there is inserted a hose-likeconstriction collet 69 which is sealingly cemented at both its endsections to the casing 67. The constriction collet 69 is made from anelastomeric material with very great resistance to wear.

In the middle longitudinal portion of the constriction collet 69 acylindrical recess 71 is present in the casing 67. Into it leads aradially aligned feed line 72 to which a connecting line is connectedoutside of the casing 67 for a fluid which can be subjected to a certainworking pressure by means of a pressure generator not shown.

The sealing device 66 is basically made the same as the sealing device65, but it is generally made shorter axially on account of the limitedspace generally available.

The loading of the guide tube 12 in the loading station is performed asfollows: with the ball cock 45 closed a rod-like tool is inserted allthe way into the sealing device 65. If the constriction collet 69 is notbrought by its elastic properties into sealing contact all around theworkpiece, pressure is applied to the fluid in the recess 71 through thefeed line 72 so that the middle section of the length of theconstriction collet 69 comes into sealing contact with the workpiece.Then the ball cock 45 is opened and the workpiece is pushed through itand through the second sealing device 66 all the way into the guide tube12. Then, as soon as the rear end of the workpiece has arrived in rangeof the first sealing device 65, the second sealing device 66 ispressurized, so that its sealing tube likewise sealingly engages theworkpiece. When the back end of the workpiece has emerged from the ballcock 45, but is still in the second sealing device 66, the ball cock 45is closed. As the workpiece continues to be advanced by means of thefeeding device of the turning machine, no more damping fluid can thenleak out.

If for reasons of space the second sealing device 66 cannot be provided,the escape of the damping fluid can also be largely prevented by usingfor the insertion of the workpiece an inserting tool having the samecross-sectional shape as the workpiece. With this inserting tool theworkpiece is inserted past the ball cock 45. Then the inserting tool iswithdrawn so far that the ball cock can be closed. Only then is theinserting tool withdrawn from the sealing device 65.

If the sealing device 65 is to be made without the cylindrical recess 71and without the feed line 72 for the fluid, it is desirable to make theconstriction collet 69, at least over a certain portion of its length,with a slight undersize with respect to the outline projection of theworkpieces. In the embodiment of the sealing device 65 previouslydescribed, in which the constriction collet 69 can be operated with afluid, this constriction collet can be slightly oversize with respect tothe outline projection of the workpieces, since this oversize will becompensated by feeding in the fluid with resulting elastic deformationof the constriction collet 69.

I claim:
 1. A feed device for a turning machine, comprising:a spindledrum having a central axis; a plurality of guide tubes each having anopening therein and a first end which faces away from said spindle drum;a holding plate having a plurality of axial passage bores therein, afront side facing toward said spindle drum, and a rear side facing awayfrom said spindle drum, said first end of each of said plurality ofguide tubes being fastened to and mounted in a corresponding one of saidaxial passage bores; a supporting frame; a bearing, disposed in saidsupporting frame, which supports said holding plate thereby allowingsaid holding plate to rotate about said central axis of said spindledrum; a connecting line in communication with said plurality of guidetubes; a common supply line connected to said connecting line forsupplying damping fluid to said plurality of guide tubes; a cover plate,disposed proximate said firs ends on said rear side of said holdingplate, which covers said holding plate at least up to a diameter withinwhich said plurality of guide tubes are disposed, said cover plate beingcoupled to said supporting frame so that it cannot rotate; a sealdisposed between said holding plate and said cover plate so that saidrear side of said holding plate is sealed from the external environment;wherein said connecting line is disposed between said holding plate andsaid cover plate and serves as a distribution passage for supplyingdamping fluid to said openings of said plurality of guide tubes, andsaid cover plate has a first passage bore therein which connects saidcommon supply line to said distribution passage.
 2. A feeding device asrecited in claim 1, wherein said cover plate has at least one passagebore therein which is aligned with one of said guide tube openings, sandsaid cover plate passage bore has an inner width which is at least equalto a greatest outside dimension of a rod-like workpiece to be insertedin said cover plate passage bore, and further comprising a closure forclosing said additional passage bore.
 3. A feeding device as recited inclaim 2, further comprising a guide which guides a movement of saidclosure relative to said cover plate between a first position wherebysaid cover passage bore is closed and a second position whereby saidcover plate passage bore is open, and an actuating device which movessaid closure between said first and second positions.
 4. A feedingdevice as recited in claim 1, wherein said cover plate has at least onepassage bore which is aligned with a center line of at least one of saidplurality of guide tubes and which has an inside width that is at leastequal to a greatest outside dimension of a workpiece to be inserted insaid cover plate passage bore, and further comprising a rotatable cockincluding an axis of rotation and a plug with a passage bore therein,said plug passage bore extending transversely to said axis of rotationand having an inside width which is at least equal to a greatest outsidedimension of a workpiece to be inserted in said plug passage bore.
 5. Afeeding device as recited in claim 4, wherein said cock is a ball cock.6. A feeding device as recited in claim 4, further comprising anactuating device and a power drive which is coupled to said actuatingdevice, said actuating device driving said cock.
 7. A feeding device asrecited in claim 2, further comprising a shut-off device disposed insaid additional passage bore, said shut-off device 1) having a passagebore therein which is aligned with said cover plate passage bore andwhich has an inside width that is at least equal to said greatestoutside dimension of said rod-like workpiece, 2) being sealinglyconnected to said cover plate and 3) being in sealing contact with saidholding plate proximate to at least one of said plurality of axialpassage bores so that said at least one of said plurality of axialpassage bores does not communicate with said distributionpassage;wherein said cover plate passage bore is connected to saidconnecting line between said shut-off device and said closure.
 8. Afeeding device as recited in claim 4, further comprising a shut-offdevice disposed in said cover plate passage bore, said shut-offdevice 1) having a passage bore therein which is aligned with said coverplate passage bore and which has an inside width that is at least equalto said greatest outside dimension of said workpiece, 2) being sealinglyconnected to said cover plate and 3) being in sealing contact with saidholding plate proximate to at least one of said plurality of axialpassage bores so that said at least one of said plurality of pluralityof axial passage bores does not communicate with said distributionpassage;wherein said cover plate passage bore is connected to saidconnecting line between said shut-off device and said rotatable cock. 9.A feeding device as recited in claim 7, wherein said closure is anactuable closure in the form of a cock having a first opening, and saidcover plate passage bore is connected to said connecting line throughsaid first opening.
 10. A feeding device as recited in claim 9, whereinsaid closure includes a second opening which is connected to saidconnecting line.
 11. A feeding device as recited in claim 8, whereinsaid rotatable cock is an actuable closure in the form of a cock havinga first opening, and said cover plate passage bore is connected to saidconnecting line through said first opening.
 12. A feeding device asrecited in claim 11, wherein said rotatable cock includes a secondopening which is connected to said connecting line.
 13. A feeding deviceaccording to claim 4, further comprising a sealing device adjacent tosaid cover plate and aligned with a center of said cover plate passagebore, said sealing device having a passage bore therein, said sealingdevice passage bore having a cross-section which corresponds to an axialprojection of said workpiece, and wherein said sealing device includes asealing member which is elastic in at least a radial direction and whichin a loose state is slightly undersized relative to said axialprojection.
 14. A feeding device according to claim 13, wherein saidsealing member has an outer circumferential surface having an annularpassage therein, and further comprising a controllable fluid feeddevices for supplying fluid to said annular passage such that at timeswhen fluid is supplied, an overpressure is applied to said outercircumferential surface.
 15. A feeding device according to claim 5,further comprising an actuating device and a power drive which iscoupled to said actuating device, said actuating device driving saidcock.